Russia's spokesman for international cooperation in fighting terrorism Alexander Zmeyovsky said that Russia is "gravely concerned" about U.S. reports of Assad's chemical weapons use in Syria, according to The Voice Of Russia.

Earlier today, the Obama administration advised Moscow that it should "pull its support" from the Assad regime.

As we've already reported, there are Russian troops in Syria, and should a fight take place, those troops would be in harm's way.

Now Washington has kindly advised Moscow that a fight will take place, and, for fear of appearing aligned with chemical weapons use, Russia will likely make its exodus.

"Should the 'red line' of chemical weapon use be crossed, I think Russia will just want to be completely removed from the situation, and make sure that they retain influence in a post-Assad Syria," Ingrid Pederson, an expert in Near East and Russian geopolitics, told Business Insider.

"Russia is very self-interested and continuing to back Assad at this point does nothing for them and in fact could hurt their image with those who may come to control Syria after Assad falls," Pederson concluded.

As if to hint at the possibility of Russia leaving Syria, Zmeyovsky "stressed" that Moscow's primary concern was that any intervention aims at immediately countering the proliferation of Assad's chemical weapons.

It's no secret that the U.S. has been constructing contingency plans for the Assad regime's collapse, as well as the event of Western military intervention. Those plans reportedly give much consideration to securing Assad's chemical weapons stockpiles.

Zmeyovsky's emphasis on that point is, at the very least, an acknowledgement of American planning for removal of Assad.